1. Field of the Invention
The present invention relates to the installation and support of electronic circuits, such as field-installable memory circuits supported in individual packages such as dice, vertical surface mount packages, lead frame packages and so forth. More particularly, the invention relates to a technique for mechanically and electrically installing such circuit devices on a support, such as a socket or connector on a printed circuit board or motherboard.
2. Description of the Related Art
A wide variety of packaging techniques have been proposed and are currently in use for supporting and interconnecting electronic circuitry, such as memory devices, add-on peripheral circuits, upgrade circuit components, and so forth. Such devices typically include an electronic circuit or circuits formed in or disposed on a support, such as a semiconductor die. The electronic circuitry on the support is designed to function with external circuitry in the ultimate application, such as in a personal computer or other electronic device. To enhance the flexibility of the overall circuit design, it is particularly convenient to provide the separate electronic circuitry in packages which can be assembled on a supporting socket either during factory installation or in the field, such as by end users, local component vendors or service personnel. In such cases, the separately packaged circuitry may be designed to be retrofitted or installed on existing circuit boards as needed such as to further enhance or upgrade the user""s system.
Individually packaged circuitry of the type mentioned above may be installed in several manners. For example, the installation of semiconductor dice may be automated in large scale manufacturing processes, particularly when the same or similar circuits are to be added to a large number of circuit boards. However, for after market or add-on circuits, such high-speed installation techniques are inappropriate. Rather, in such applications the circuit package is typically shipped and handled individually or in small groups. Vendors or end users often purchase the circuit packages and individually install the packages in the final application, such as by pressing conductive leads or pads provided on an edge of the package into corresponding sockets in a support or interface connector by hand or by means of conventional tools, such as tweezers.
Such techniques for installing circuit devices suffer from several important drawbacks. First and perhaps most importantly, the circuit device package itself may be quite fragile and easily damaged during handling and installation. Similarly, the circuit board and socket on which the package is installed may often be easily damaged when excessive or improperly-directed force is applied to it during installation. Moreover, increasingly complex add-on circuitry requires a large number of conductive pads or pins extending from the circuit package. These delicate features of the components stand a much greater risk of damage to either the circuit package or to the support in which the package is installed due, again, to excessive force and misalignment. In addition, where the circuits are manually handled and installed, serious damage to the circuits can result from static charges inadvertently conveyed to the circuits by the user or service personnel, or from oils present on the installer""s hands.
Various approaches have been proposed and are currently in use for addressing the shortcomings of conventional circuit package installation techniques. For example, the packages supporting the add-on circuitry may be constructed in an increasingly robust manner in an attempt to provide a sturdy framework capable of withstanding handling during transport and installation. However, such packaging adds to the size and cost of the circuitry, and may not effectively reduce the risk of damage to the circuit on which the add-on package is installed. Moreover, to the extent that such techniques still require manual handling and installation, risks associated with static charges and oil from handling may be equally unavoidable.
There is a need, therefore, for an improved technique for handling and installing circuit devices that addresses such drawbacks. In particular, there is a need for an improved system for holding or supporting circuit devices, particularly fragile devices formed on unprotected semiconductor dice, or on dice with limited mechanical protection, during transport, handling and installation. Ideally the technique would reduce or eliminate the need to physically handle the circuit package itself, and would provide for appropriate alignment and securement of the circuit package in a socket or connector.
The present invention provides a technique for installing circuit devices which is designed to respond to these needs. The technique offers a system both for storing and transporting such devices, as well as for facilitating their installation in an application. The technique may be employed with a variety of device packages, but is particularly well suited to direct die connect sockets, lead frame packages, and the like. Moreover, the technique provides a mechanism for storing and installing a single such device, and which may be adapted for installation of a plurality of similar or different devices in a single unit.
In a favored approach, the technique employs a holder or case designed to enclose the circuit device during transport. The device holder also facilitates placement and alignment of the circuit device for installation. Moreover, the device holder permits ejection of the device for installation without requiring direct contact or handling by the user or service personnel. The technique may be further adapted to facilitate manual installation of a large number of similar devices, such as by vendors, from a tool which stores and ejects a series of similar devices from a stack. In its various embodiments, the technique may be employed with custom-designed component packages, or with packaged circuit devices of conventional design without requiring special adaptation of the external configuration of the packages.
Thus, in accordance with a first aspect of the invention, an apparatus is provided for installing an electronic circuit device on a support. The support includes a plurality of first conductive elements. The device has a plurality of second conductive elements disposed adjacent to at least one edge thereof. The first conductive elements are configured to contact the second conductive elements when the device is installed on the support. The apparatus includes a holder and a manually actuatable ejector. The holder is configured to receive the device and to align the first conductive elements with the second conductive elements. The ejector is configured to extend at least partially into the holder and to urge the device into an installed position wherein the first conductive elements contact respective second conductive elements. The ejector may conveniently include a slot in which the device is aligned. The ejector enters into the slot to press the device from the slot and into engagement on the support upon manual actuation of the ejector. The holder may also conveniently include a plurality of such slots to facilitate transportation, storage and installation of a corresponding number of circuit devices.
In accordance with another aspect of the invention, a tool system is provided for installing a semiconductor device on a receiving support. The device includes a plurality of conductive elements disposed adjacent to an edge thereof. The conductive elements are received by an interface region of the support. The tool system comprises a holder and a manually operated ejector. The holder has side walls forming a cavity for retaining the device. An opening is provided from the cavity for dispensing the device on the support. The ejector is configured at least partially to enter into the cavity and to urge the device through the opening onto the interface region. A second opening may conveniently be provided in the slot for loading or charging the device prior to installation. Features may be provided on the holder which cooperate with registration features on the receiving support to ensure proper alignment of the device with the interface region prior to installation.
The ejector may be configured as an elongated tool which receives a stack or a series of semiconductor devices. The devices in the stack are urged toward a dispensing slot by a spring mechanism or similar arrangement. Upon actuation of the ejector, the device adjacent to the slot is forced through the slot for installation, followed by indexing of the next device in the stack toward the slot for installation.
The invention also provides a method for installing an electronic circuit device on a support. The circuit device is of the type having a plurality of first conductive elements configured to contact second conductive elements in an interface region of the support. In accordance with the method, the circuit device is positioned in a holder, the holder having a recess for receiving the circuit device. The holder is then positioned on the interface region. The circuit device is manually urged from the recess to electrically couple the first conductive elements to the second conductive elements, thereby installing the circuit device on the interface region of the support. The holder may conveniently guide the circuit device from the recess during its ejection therefrom. During the positioning of the holder on the interface region, registration elements disposed on the holder and the support may be mated to properly align the circuit device over the interface region.
In accordance with a variation on the method, a plurality of circuit devices are positioned in a dispenser: The dispenser is located on an interface region of a support. At least one of the circuit devices is then manually urged from the dispenser onto the interface region. First conductive elements on the circuit device thus dispensed are thereby brought into contact with second conductive elements of the support. The circuit devices positioned in the dispenser may be conveniently separated from one another by partitions formed in the dispenser or may be positioned in a stack directly contacting one another in the dispenser.